You can install our site as a web app on your iOS device by utilizing the Add to Home Screen feature in Safari. Please see this thread for more details on this.
Note: This feature may not be available in some browsers.
I know because every time the silly software update “factory resets” the system I have to re-enter favourites on both wife’s and my profiles. Bloody annoying. They also didn’t come back from the cloud unlike some of the other settings (from my cloud-synced, email-based Tesla account).
I've had all my favourites disappear after an update too, but they definitely are stored in the cloud-synced account, because my favourites appeared in the Tesla service centre loaner vehicle. No idea how they get lost when an update goes wrong though.